The present invention relates to electrical switchboards for accommodating various electrical devices, e.g., switches, circuit breakers, transformers, motor controllers, etc., utilized in the distribution and utilization of electrical power. Such switchboards typically include one or more side-by-side cabinets having a metallic framework for mounting the cabinet sides, doors, etc. The framework also serves, via elaborate bracketing and insulating members, to insulatively mount and isolate the vertical and horizontal buses, in addition to the various electrical devices. Such conventional techniques for mounting the devices and buses are expensive and take up considerable space. Consequently, the cabinets must have considerable depth to accommodate the mounting provisions and to provide space in the rear for routing of the various cables used to electrically connect the loads to the ends of the device load straps. Also the cabinets must have considerable width to provide adequate electrical clearance between buses of different polarity or voltage. Moreover, elaborate isolating or barrier members must be provided to shield installation and maintenance personnel from live parts.
Further complicating the construction of existing electrical switchboards is the fact that they are typically required to accommodate a wide variety of electrical devices of varying physical sizes and ratings. Consequently, the manufacture of such switchboards, to provide the requisite versatility, requires a large inventory of variously sized parts, otherwise special drilling, cutting and forming operations must be performed during assembly.
In partial solution to these and other drawbacks of the prior art, U.S. Pat. No. 3,308,348 discloses a switchboard construction utilizing insulative mounting blocks for the vertical buses. However, these individual blocks are not effective as rear compartment barriers since they are mounted to the switchboard framework in vertically spaced relation. Moreover, they have a relatively large depth dimension and thus do not permit significant reductions in cabinet depth.
It is accordingly an object of the present invention to provide an improved electrical switchboard design utilizing a unique, modular mounting panel of electrically insulative material in lieu of myriad insulating and bracketing elements.
An additional object of the invention is to provide an electrical switchboard of the above character which requires less cabinet space than conventional designs.
A further object of the invention is to provide an electrical switchboard of the above character which includes barrier provisions for effectively shielding the electrically live parts thereof, thus providing increased safety for installation and maintenance personnel.
Still another object is to provide an electrical switchboard of the above character which is readily adapted to accepting various sizes and ratings of control units, thus simplifying fabrication and assembly.
Yet another object is to provide an electrical switchboard of the above character which is economical to manufacture, and efficient to install and maintain.
Other objects will in part be obvious and in part appear hereinafter.